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Spencer DA, Venkataraman M, Higgins S, Stevenson K, Weller PH.Spencer DA, et al. Among authors: weller ph.Respir Med. 1994 Oct;88(9):671-5. doi: 10.1016/s0954-6111(05)80065-4.Respir Med. 1994.PMID: 7809440
Green A, Griffiths P, Williams J, Weller P.Green A, et al.Arch Dis Child. 1987 Mar;62(3):317-8. doi: 10.1136/adc.62.3.317-a.Arch Dis Child. 1987.PMID: 3566333Free PMC article.No abstract available.